Agents for combating pests and a method for killing pests



Patented Apr. 15, 1952 AGENTS FOR. COMBATING PESTS AND A METHOD FOR KILLING PESTS- Hans Gysin, Basle, Switzerland, assignor to J. R.

Geigy A. G., Basle, Switzerland, a Swiss com- No Drawing. Application November 18, 1949, Se-

rial No. 128,247. In Switzerland November 16,

12 Claims. 1

This invention relates to a new class of chemical compounds and to compositions and methods for utilizing the biological properties of said compounds.

The new class of chemical compounds consists of dihydroresorcinol esters of carbamic acids having the general formula wherein R1 and R2 each represent hydrogen or a methyl group and R3 and R4 each represent the same or a different lower aliphatic hydrocarbon radical.

I have discovered that this new group of compounds is suitable for combating pests such as insects and other arthropods and that they have not only a lethal action but also a repellant effect on various troublesome insects.

I have discovered further that one compound of this new group of compounds, namely, 5.5-dimethyl-dihydroresorcinol-dimethyl-carbamate is unique in that it has a strikingly higher lethal effect upon insects than the other compounds of the group even including those closely related to it in structure. This new compound has a very active lethal effect against many insects, namely, e. g. flies (including files which have shown resistance to the action of the well-known insecticide DDT), mosquitoes, gnats, ticks, plant lice, aphids, bed-bugs and ants. My invention. includes this new compound 5.5-dimethyl-dihydroresorcinol-dimethyl-carbamate and pesticide compositions and methods based on the unique properties of this compound.

I have discovered further that one other compound of this new group of compounds, namely, 5.5 dimethyl dihydroresorcinol diethyl carbamate possesses unique properties as an insect repellent. While this compound is less lethal to insects that the corresponding dimethyl-carbamate, it has a repellent efiect on blood-sucking insects, such as mosquitoes and gnats greater than that of the dimethyl-carbamate or of any other member of the group. My inventionincludes the new compound 5.5-dimethyl-dihydro resorcinol-diethyl-carbamate and insect repellents based on the unique properties of this compound. I

These new compounds can be prepared by reacting a dihydroresorcinol of the general formula or its salts such as, for example, the alkali salts, with a carbamic acid derivative of the general formula wherein X represents chlorine or bromine and R1, R2, R3 and R4 have the meanings defined hereinbefore. The reaction may be carried out in the presence or absence of inert solvents such as, for example, benzene, acetone, dioxan or ethyl acetate. nol is used, it is advantageous to add an acidbinding agent.

The dihydroresorcinols which can be used as starting materials in making the new compounds are known. Dihydroresorcinol itself can be prepared, e. g., by partial catalytic hydrogenation of resorcinol in the presence of basic compounds. 5.5-dimethyl-dihydroresorcinol (dimedone) may conveniently be prepared by condensing mesityl oxide with malonic ester by Michaels method, followed by saponification and decarboxylising (Vorlander and Erig, A. 294, 314 (1897)). 5- methyl-dihydro-resorcinol can be prepared, for example, by condensing ethyl crotonate with ethyl aceto-acetate followed by saponification and decarboxylising (v. Schilling and Vorlander, A. 308, 192 (1899)).

Many examples of the carbamic acid halides of the general formula given above are known. They may be produced in very good yield by reacting secondary, lower molecular aliphatic amines with dihalide derivatives of carbonic acid. When they are produced in non-reactive solvents, the solutions thus obtained may be directly reacted with the dihydroresorcinols.

Examples of secondary, lower molecular aliphatic amines of the general formula which may be used are: dimethylamine, diethylamine, methyl-ethylamine, di-n-propylamine, diallylamine, methyl-isopropylamine, ethyl-allylamine, di-n-butylamine, n-butyl-isobutylamine, methyl-n-butylamine, diamylamine.

The following examples serve further to illustrate and explain the manufacture of the new compounds. Parts are to be understood as parts by weight and temperatures are given in degrees centigrade.

EXAMPLE 1 parts of 5.5-dimethyl-dihydroresorcinol are dissolved in the calculated quantity of sodium carbonate solution and evaporated to dry- When an uncombined dihydroresoroiness. The residue is extracted with absolute alcohol to free it from inorganic salts and after removal of the solvent the monosodium salt is The product is 5.5-dimethyl-dihydroresorcinol-dimethyl-carbamatehaving :the formula left in a dry form which can be easily pulverized. CH CH The well pulverized salt is suspended in 800 parts 5 a of dioxan and 135 parts of diethyl-carbamyl v -0CON chloride are added drop by drop to the suspeng fi, sion. The reaction mixture is then heated" at 90-1110 for 12 hours and the sodium chloride f if g h igfiffi pmpemes' Bolhng pom formed removgd from the sphmon q Still In a high vacuum, the compound boils at 122- warm, by filtering under suction. After tne sol- O vent has been distilled off the residue is rectified 124' under m essure crystalhzmg to y vacuum distillation form a YBIIOWlSh-Whlt crystalline mass with The product has a boiling point of 131-134 at i g g g g ggg ggg 55331 2 f g gi g 0.3 mm. pressure and is aiaintly yellowish liquid. 15 Solvents l y g ig s ii i gg ig g@2353? Thefollowing compounds can-also be prepared by the methods described above: fi 0H\3GH2 EH /C2Hs R1 C \CH R:

(3OCO-N l 4 -O. "(JO N c 1 on, 01H: R: g R

R, R3 a. t- B121 SllIG H CH: -cn= -123 0.6 H CHa -C2H:j 118-120. 0.25 H -C2H5 -C2Hs 122-124. 1 0.25- H CH: C4H9 132-1sa 0:25 H v C 411 C4H9 0. 8. H OH;-CH=CH1 CHz-CH=CH1 142-144 0.15 n oH= -on= 112-114 0.2- H CH: C2H5 118 0.03 H C2Hl C2H5 136 0. 7 H C1Hw c.11@ 145-117 0.1 11 C1Hd(iso) 0.1101150) 133-115;) 0.08 CH; CH:- C:Hs 113-116 0.1 CH: CH: --C4H0 146-148 (12 CH: C:H7 C3H1 130 0. 2 is CH; -C1Ho c.H -157 0.2 CH3 CH1CH=CH2 CH1CH=CH: 142-141 0.1 17-.. CH3 CH3 -C5Hn C5H11 -167 0.25"

EXAMPLE 2 All these new compounds have, to some. extent,

70 parts of- 5.5-dimethyl-dihydroresorcinol are mixed-with 500 parts of ethyl acetate. Next '75 parts of anhydrous potassium carbonate and 68 parts of diethylcarbamyl chloride--= are added. The mixture is heated to boiling for 20 hours. The warmreaction mixture is next freed from inorganic salts andany unreacted potassium salt of 5IS dimethyl-dihydroresorcinol 1 which may be present, by filtration under suction. The diethyl-carbamate is then purified as describedin Example 1.

140 parts of: 5;5-dimethyl-'dihydroresorcino1 and 97 parts of finely pulverized potassium carbonate are suspended in380 parts of benzene and the mixture stirred, while being kept refluxing. The water formed onneutralization is distilled off azeotropically. After the water has. all been separated, the suspensioniscooled to-60' and a solution of 108 parts of dimethyl-carbamyl chloride in.500 partsof benzene is added all at once. The resulting suspension is refluxed for 12 hours and any water which may form is'removed from the .1 system by azeotropic distillation. After cooling, .thelmixture is poured into 300 parts of water, .the whole .isthoroughly shaken up and the benzene layer removed. The aqueous solution is shaken up with benzene and the lumped benzene solutions are-washed-with water until neutral. The benzene-isnext distilled off under normal pressure andthe-residue fractionated in awater-jet'vacuum or-in a-highvacuum: Yield, ca. 200 parts.

both a' lethal and a repellantfieffect on insects,

resorcinol-diethyl-carbamate is greaterthanthatof the other compounds.

My, invention includes also pesticide and -in-. .seot repellent compositionsand methods. by. means'of which the biological'properties oitha new compounds may be made avaliable anduseful in a number ofdifferentfields.

EXAMPLE 4 Dusting agent 10 parts of 5.S-dimethyl-dihydroresorcinol-di methyl-carbamate areground together; with 90- parts of talcum as finely as possible. The stick ing power of .the powder can. be increased, if'desired, by'adding a-mixture of. 2 parts-of avliquid fatty'acid and .1 part of. quenched lime. Sucha' dusting agent, can be used, e. g.', for combating pests in. agriculture and in. the household.v Itis: bed-huge:

particularly efiective against flies, plant lice and aphids.

Changes. may be madewin the-dusting agent described without departing from my invention. Thus the talcum may be. replaced by calcium carbonate in the form of: whiting or ground limestone, kaolin, bole, bentonite, powdered magnesia, kieselguhr, boric acid," tricalcium phosphate, also powdered wood, powdered cork and 1 other materials of a vegetable nature.

strikingly.

50 parts of 5.5-dimethyl-dihydroresorcinol-dimethyl-carbamate, 40 parts of chalk, kieselguhr or bentonite, 2.5 parts of soda ash, 2.5 parts of casein and 5.0 parts of the sodium salt of dibutyl-n'aphthalene-sulphonic acid are ground up together as finely as possible. On stirring up with water, there is obtained a spraying agent excellently suited for combating ticks on animals or flies in stalls where animals are kept.

In the spraying agent which has been described, the casein may be replaced by another dispersing agent and the sodium salt of dibutylnaphthalene-sulfonic acid may be replaced by another wetting agent without departing from my invention.

Systemic insecticide The spraying agent described in Example 5' is also indicated for combating plant lice (aphids) and other sucking insects. It should be noted here that also those plant lice not directly reached by the spray itself are also killed as the active substance penetrates into the sap-stream of the plant and the sap-sucking insects are thereby destroyed. By special additions to the above spraying agent, it is possible to hinder the evaporation of the active substance and to increase the resistance to rainfall. In this way, it is possible to attain a certain residual effect against plant lice, as new amounts of active substance are constantly going into the sap-stream from the spray deposit. In this connection, for example, natural and synthetic resin, water glass, dextrin, starch, adhesives etc. can be used as additives.

EXAMPLE 6 Spraying agent (solution) (a) 2 parts of 5.5-dimethyl-dihydrorescorcinoldimethyl-carbamate are dissolved in 98 parts of kerosene.

-(b) 2 parts of 5.5-dimethyl-dihydrorescorcinoldimethyl-carbamate and 3 parts of 1.l-bis- (p-chlorophenyl)-2.2.2-trichlorethane are dissolved together in 95 parts of kerosene.

Both solutions are excellently suited, for example, for combating flies in dwellings as well as in storage-depots and slaughterhouses.

In the sprays described, the kerosene may be replaced by similar mineral oil fractions or methyl naphthalene, xylenes and the like without departing from my invention.

By substituting kerosene by lower boiling solvents, such as trichlorethylene, tetrachlorethane or ethylene chloride, the spraying agent may be made suitable for spreading the active ingredient in the form of a mist.

EXAMPLE 7 Spraying and impregnating agent parts of 5.5-dimethyl-dihydroresorcinol-dimethyl-carbamate are dissolved in 80 parts of isopropyl alcohol. The solution is miscible with water in all proportions, without any active. submiscible solvents, such a lower alcohols or ketones.

EXAMPLE 8 Fly 8137111] 2 parts of 5.5-dimetyhl-dihydroresorcinol dimethyl-carbamate are dissolved in 2 parts of ethyl alcohol and diluted with 96 parts of water. The

solution is valuable as a household fly spray, but

may also be used for plant-protection, for combating animal and human ectoparasites, for im-' pregnating textiles or as a space spray.

It is sometimes desirable to combine one of the new compounds with a bait or lure for insects to be killed. In this way a highly effective composition for destroying flies and other insects is produced, because it then also acts as stomachpoison. Examples of this composition are as follows:

EXAMPLE 9 Fly spray capable of flying and a few hours later all the flies were dead. The same result was obtained by releasing 200 more flies-in the same room a few days later without repeating the spraying of the wall.

The solution may also be used to impregnate paper which then becomes effective as fly-paper. To produce the fly-paper, a sheet of filter paper is soaked in the solution and then dried. The effectiveness of this filter paper has been proved by the following test:

A piece of the filter paper (20 x 30 cm. in size) was placed at a suitable place in a room which contained 200 fiies. After two hours all the fiies were incapable of flying and a few hours later they were all dead. The fly-paper retained its activity during several days.

EXAMPLE 10 EXAMPLE 11 2 parts of 5.5-dimethyl-dihydroresorcinoldimethyl-carbamate, 1 part of silica aerogel, 97 parts of sugar are ground together and added to a mixture of 10 parts of malt extract and 50 parts of 33% homogenous gum arabic solution.

The viscose phase obtained can be pasted on fabric or impregnated in paper. The foils made 7 therefrom. have a good action against flies. especially when hung up in rooms.

EXAMPLE .12

Emulsion 20 parts, of 5.5-dimethyl-dihydroresorcinoldimethyl-rcarbainate, 25 parts of acetone,.20 parts.

of xylene and 35 parts of, a higher molecular;

also, killed, as the activesubstance penetrates into the sap-stream of the plant and the sap sucking insects; are thereby, destroyed.

If the emulsion, suitably diluted, is poured on. the earth, then plant lice and other sucking insects on the plants which take in the substance through the roots can also be destroyed.

When plant stems which are attacked by plant lice,- are treated with a dilute emulsion, the plant lice are also destroyed by theactive substance which is absorbed into the sap-stream.

In the emulsion above described, the condensation product which serves as an emulsifying agentmay be replaced by a compound of a cationactivenature, such as. quaternary ammonium compounds, as Well as anion-active. agents such as soap, soft soap, aliphatic mono-esters, of sulfuric acid and aliphatic-aromatic sulfonic acids; and the acetone and xylem maybe replaced by other solvents such as alcohols, cyclohexanone, benzene, toluene, tetrahydronapthar lene, alkylated naphthalenesand phthalic. acid esters, without departing from my invention.

EXAMPLE 13 Insect repellent (liquid) 20; parts of 5.5-dimethyl-dihydroresorcinoldiethyl-carbamate are dissolved in 80 parts of lsopropyl alcohol. When applied to the skin or to articles of clothing or linen, this agent has a long-lasting insect-repellant effect.

Other water-soluble solvents may be substitutedfor the isopropyl alcohol in thiscomposition.

EWPLE 14 Insect repellent (ointment) 20 parts of 5.5-dimethyl-dihydroresorcinoldiethyl-carbamate are dispersed in 80 parts of Vaseline or other ointment base. When applied to the skin, theresulting ointment has. a longlasting, repellant effect against mosquitos, fiies, and gnats.

EXAMPLE 15 parts of 5.5-dimethyl-dihydroresorcinoldimethyl-carbamate-are,mixed with partsyof wheat flour, 52 parts of wood meal, 3 parts of potassium nitrate and 130 parts of water. The mass is shaped under'pressure, e. g., in a spiral shape and dried.

When slowly burned, this composition has excellent insecticidal properties.

Other combustible powderedmaterials may be substituted for the wheat flour and wood meal inthis composition;

In all the compositions which have been described, the active ingredient named may be replaced by any member of the aforesaid groupv 8. of new compoundswithout departing from my invention, but the compositions thus produced are in generallessefiectivethanthosecontaining;

the particular active ingredients specified in the description of} the compositions.

What I claim, is:

l. The. method of killing insects which comprises distributing a compound correspondingto the formula wherein R1 and R2- each represents a member selected from the group consisting of hydrogen and methyl and R3 and R4 each represents a lower aliphatic hydrocarbon radical to eiTect contactofsaid compound with the insects.

2;,The, method, of killing insects which. comprises distributing 5;5 dimethyldihydroresorcinol-dimethyl-carbamate to effect contact of said compound with the insects.

3; A" fiy-spray comprising as essential active in"- gredient 5.5-dimethy1-dihydroresorcinolrdimethyl-carbamatc and a water-soluble solvent therefor.

4. A fly-spray comprising as essential active ingredient 5.5-dimethyl-dihydroresorcinol-dimethyl-carbamate and an insecticide spray oil.

5. A esticidal solution for killing flies and other insects, comprising 5.5-dimethyl-dihydroresorcinol-dimethyl-carbamate and sugar; dissolved inwater;

6. A pestic-idal dusting agent comprising a minor proportion of 5.5-dimethyl-dihydroresore cinol-dimethyl-carbamate and a major-proportion of inert powder.

7. A pesticidal spray base comprising 5.5-dimethyl dihydroresorcinol dimethyl oarbamate, inert powder and an emulsifying agent.

8. A mosquito repellent comprisingas-essen: tial active ingredient 5.5-dimethyl-dihydroresolie cinol-diethyl-carbamate and isopropyl alcohol.

9,. A compound corresponding to the formula-- 11. 5.5-dimethyl dihydroresorcinol diethyl carbamate.

l2. fi-methyl dihydroresorcinol dimethyl carbamate.

HANS GYSIN.

REFERENCES CITED The following references are of record in, the, file of this" patent:-

UNITED STATES PATENTS Name Date- Kilgore Feb. 16, 1937 Number (Other references on followingpagc) OTHER REFERENCES Klingenfuss, Chemical Abstracts 31, column 2538 (1937).

Eddy et aL, "Further Tests Chemical Abstracts, Volume 41, columns 3575 to 3577 5 1ication date August 1, 1947). Pages 18, 23, 28 ,j(2f' entries), 39, 0-6185 N-4(1-diethy1amino ..pentyl) urethane, 0-553 urethane, 0-2559 meth- "jf'yle'ne bis-(dimethyldihydroresorcinol), 0-2560 -jjoenzylidene bis- (dimethyldihydroresorcinol) and f0 6409 N,N-dicyc1ohexy1 carbamic acid, methyl ester, respectively, considered particularly pertin'ent. 

1. THE METHOD OF KILLING INSECTS WHICH COMPRISES DISTRIBUTING A COMPOUND CORRESPONDING TO THE FORMULA 